SAR Journal. Volume 4, Issue 2, Pages 47-51, ISSN 2619‐9955, DOI: 10.18421/SAR42-01 June 2021.

Computer-Aided Manufacturing of a Shaft for Wood Chipper using Autodesk Inventor 2020

Peter Tirpak, Peter Michalik, Jozef Macej

Faculty of Manufacturing Technologies with a seat in Presov, Technical University of Kosice, Sturova 31, 080 01 Presov, Slovakia

Abstract – The article deals with the use of CAD / The basis of the wood chipper consists of two CAM software Autodesk Inventor in the production of rotating shafts with blades. One shaft rotates opposite the shaft. CAM programming is very important in the the other shaft. The wood waste is drawn between the field of engineering because it speeds up the process of rotating blades, which approach each other and manufacturing parts and enables the production of separate the pieces of wood. their complex shapes. The article describes the programming of , , and threading of the shaft. The programming was followed by the production of the shaft. The manufactured shaft met the dimensions according to the technical documentation and was subsequently used in the assembly. Keywords – Milling, Turning, Drilling, Threading, CAD, CAM, CNC programming, CNC machining

1. Introduction

The shaft described in this article is part of a wood Figure 1. Wood chipper design - complete assembly chipper which can be seen in Figure 1. This type of In Figure 2 we can see a detail of the rotating wood chipper is powerful, durable and reliable. The shafts with blades. The blades are fixed to the shaft wood chipper is designed for processing garden with screws that allow adjusting the position of the waste as tree branches with a diameter of up to 40 blades, so that there is a minimum distance between mm. Chopped waste from the garden can be used in opposing blades during wood cutting. Thanks to the compost, or it is possible to use the chopped wood as screw connections, the blades can be easily removed fuel. and sharpened, or completely replaced. The wood chipper chassis and blades were made of steel plates, using a CNC plasma cutting machine. DOI: 10.18421/SAR42-01 https://doi.org/10.18421/SAR42-01 Corresponding author: Peter Tirpak, Technical University of Kosice, Faculty of Manufacturing Technologies with a seat in Presov, Sturova 31, 080 01 Presov, Slovakia. Email: [email protected] Received: 08 April 2021. Revised: 11 June 2021. Accepted: 16 June 2021. Published: 28 June 2021. © 2021 Tirpak Peter, Michalik Peter & Jozef Macej; published by UIKTEN. This work is licensed under the CC BY-NC 4.0 licence.

The article is published with Open Access at: www.sarjournal.com Figure 2. Wood chipper design - detail on rotating blades

SAR Journal – Volume 4 / Number 2 / 2021. 47 SAR Journal. Volume 4, Issue 2, Pages 47‐51, ISSN 2619‐9955, DOI: 10.18421/SAR42‐01 June 2021.

The shafts for the blades were made of a steel Subsequently, a turning tool was selected. For the square bar grade S355 with dimension rough machining of the shaft was selected a blade 35x35x170mm. The production of the shaft consisted turning knife from the manufacturer Sandvik of four production operations - turning, milling a Coromant, with a cutting insert type CNMG 120404- keyway, drilling screw holes and threading. A CNC PM 4425 [3]. In Figure 5 we can see the tool settings and a vertical machining centre were required in the CAM module. for the production of the shafts. CAD/CAM software Autodesk Inventor 2020 was used to program CNC machines. During production, the highest demands were placed on the precise production of shafts diameters on which bearings were pressed and a gear wheel was placed.

2. Creating a Program for CNC Turning

First, a 3D shaft design was created in Autodesk Inventor 2020 software. 3D modeling is the necessary stage the geometry of the part is designed in. In the modern product engineering, describing in Figure 5. Autodesk Inventor CAM module - turning tool terms of geometry of a part cannot be completely settings for roughing separated from taking into account the technological criteria. Quality of the outcome of the conception After setting the turning tool, the cycle for process is strongly influenced by the level of roughing the shaft profile was selected and the integration of the constructive and technological machining area was defined. Figure 6 shows the aspects of the stage of designing [1]. parameters settings of the turning cycle. First, the Figure 3 shows the design of the manufactured shaft was roughly machined to a diameter of 25,5 shaft. In the picture we can see two turned parts at mm. The turned diameter was produced with an the ends of a shaft with a diameter of 25mm for a addition of 0,5 mm in diameter. length of 45mm and 17mm. Bearings will be pressed onto these parts of the shaft. The Autodesk Inventor CAM [2] module was used to create a program for a CNC lathe. The first step in programming was to define the workpiece and zero point, which are shown in Figure 4.

Figure 3. Shaft design in Autodesk Inventor 2020 software

Figure 6. Autodesk Inventor CAM module - setting the profile machining cycle for roughing

During roughing, speed S of 700 rpm and working feed F 0.10 mm per revolution were chosen. Lower speeds and feeds were set due to an intermittent cut when turning a square bar. Figure 7 shows the

Figure 4. Autodesk Inventor CAM module – workpiece generated tool paths for rough machining to a and zero point definition diameter of 25,5 mm.

48 SAR Journal – Volume 4 / Number 2 / 2021. SAR Journal. Volume 4, Issue 2, Pages 47‐51, ISSN 2619‐9955, DOI: 10.18421/SAR42‐01 June 2021.

Figure 7. Autodesk Inventor CAM module - shaft Figure 10. Autodesk Inventor CAM module – shaft roughing tool path finishing tool path

Roughing was followed by finishing to a final When finishing the shaft, speeds S of 1200 rpm shaft diameter of 25mm. The tool was changed to a and working feed F of 0.20 mm per revolution were turning knife Sandvik Coromant with cutting insert chosen. By increasing the speed and the working type VNMG 160412-PM 4335 [4]. In Figure 8 we feed, the required roughness of the machined part of can see the definition of the parameters of the the shaft was achieved. finishing tool. After the two machining cycles described in this chapter, the shaft was machined at one end to a diameter of 25mm to a length of 45mm. Subsequently, the shaft was turned in the opposite direction and the turning was repeated from the other side. The same cycles and settings were used. Only another machining area with a length of 17 mm was selected.

3. Creating a Program for Milling of a Keyway

Turning was followed by milling of the keyway,

which was used to connect the shaft to the gear Figure 8. Autodesk Inventor CAM module – tool settings wheel. The keyway was milled to a diameter of for finishing Ø25x45mm. The width of the keyway was 6mm. The turned shaft was clamped in a vice on a vertical The profile machining cycle was selected again for machining centre. The procedure for milling programming the final dimension Ø25x45mm. The programming was the same as for turning selected machining shape was the same as when programming using machining cycles. The first step roughing the diameter 25,5mm, but during finishing was to define the workpiece and set the zero point to the addition of 0,5mm was turned and thus the the centre of the workpiece. This setting is shown in diameter 25mm was achieved. The profile machining Figure 11. settings are shown in Figure 9. Only one toolpath was created for finishing, as one can see in Figure 10.

Figure 11. Autodesk Inventor CAM module – workpiece and zero point definition for keyway milling

Subsequently, the tool was selected. We decided to use a double-edged grooving cutter with a diameter of 6 mm. The selection of the milling tool is shown Figure 9. Autodesk Inventor CAM module – setting the profile machining cycle for finishing in Figure 12.

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4. Creating a Program for Drilling and Threading

At the end of the production of the shaft, it was necessary to make six holes through the entire shaft with an M8x1.25 thread. The production of threaded holes consisted of three steps:

. spot drilling . drilling . threading

Figure 12. Autodesk Inventor CAM module – tool We first created spot drills to guide the drill. Spot selection for milling drills were also used to chamfer the edge of the hole before threading. We chose a spot drill with a After defining the tool parameters, the machining diameter of 16 mm and its settings and parameters cycle for milling was selected. The keyway was are shown in Figure 15. After this setting, the drilling milled in layers 1 mm thick. Figure 13 shows the cycle was selected and points for spot drilling were cycle setting. After setting up the milling cycle and marked. The drilling depth was set to 1mm. setting up the milling tool, the CAM module in Autodesk Inventor generated paths for milling the keyway. These toolpaths are shown in Figure 14.

Figure 15. Autodesk Inventor CAM module – tool selection for spot drilling

This was followed by drilling holes with a diameter of 7,7 mm. The drilling was to a depth of 38mm so that the hole was drilled through the entire shaft. A carbide drill with internal cooling was used as a tool. Its parameters are shown in Figure 16.

Figure 13. Autodesk Inventor CAM module – milling cycle setting

Figure 16. Autodesk Inventor CAM module – tool selection for drilling

After drilling the first three holes through the entire shaft, a program stop followed. The shaft was shifted 90 ° in the vice and the same drilling cycles were used again to drill three more holes. After drilling the tap holes, threading followed as Figure 14. Autodesk Inventor CAM module – toolpaths for milling the keyway the last operation. An M8x1,25 machine tap was used

50 SAR Journal – Volume 4 / Number 2 / 2021. SAR Journal. Volume 4, Issue 2, Pages 47‐51, ISSN 2619‐9955, DOI: 10.18421/SAR42‐01 June 2021. for threading. Figure 15 shows the parameters of the keyway was milled and threaded holes were made. threading tool. The thread cycle was selected and the After finishing on the machining centre, an additional holes for threading were marked. The threading deburring of the shaft followed. The dimensions of depth was 17,5mm. This depth has been defined so the shaft were measured with a calliper. All that the tap is not destroyed during threading. dimensions were adhered to according to the Threading was similar to drilling, but the shaft was production documentation. The shaft has been rotated 90° in the vice four times. After each rotation released for mounting. Figure 19 shows the finished of the shaft, three threads were made. Figure 18 shaft. shows the toolpaths for drilling and threading a manufactured shaft.

Figure 19. Shaft after production

6. Conclusion

In this article, we have tried to show the benefits of

computer aided design and computer aided Figure 17. Autodesk Inventor CAM module –tool manufacturing. Thanks to Autodesk Inventor 2020, selection, metric machine tap M8x1,25 we were able to design a complete wood chipper. We have successfully used the CAM module to generate programs for the CNC lathe and CNC vertical machining center needed to manufacture the parts. The shaft whose production we have described in this article fully complies with the project documentation.

References

[1]. Drăgoi, M. V. (2010). Advances in CAD/CAM Technologies. New Trends in Technologies: Devices, Computer, Communication and Industrial Systems, 67. DOI: 10.5772/10441 . [2]. Inventor CAM - Integrated CAM software for Inventor simplifies CNC programming processes. Retrieved from: https://www.autodesk.com/products/inventor- Figure 18. Autodesk Inventor CAM module – drilling cam/overview?plc=PDCOLL&term=1- and threading toolpaths YEAR&support=ADVANCED&quantity=1 , [accessed: 22 February 2021]. 5. Shaft Production [3]. Sandvik Coromant metal cutting tools (a). Retrieved from: A semi-finished product in the shape of a square https://www.sandvik.coromant.com/en- bar with dimensions of 35x35x170mm made of steel gb/products/pages/productdetails.aspx?c=CNMG%20 grade S355 was turned on a CNC lathe Viper VT- 12%2004%2004-PM%20%20%20%204425, 28BL-1500. Based on the program that we created [accessed: 22 February 2021]. using the CAM module, we first machined the shaft [4]. Sandvik Coromant metal cutting tools (b), ends to the required diameter of 25 mm. After Retrieved from: turning, the shaft was clamped in a vice on a https://www.sandvik.coromant.com/en- Pinnacle 1700s vertical machining centre, on which a gb/products/Pages/productdetails.aspx?c=VNMG%20 16%2004%2012-PM%20%20%20%204335 , [accessed: 25 February 2021].

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